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12
R
EDUNDANCY
S
UPPORT
The unit supports several types of redundancy. While each redundancy module is aimed to solve different
problems, the system handles all of the modules in a similar way, providing some general parameters to control the
switch delay and which triggers should be active for each module.
12.1
I
NPUT
R
EDUNDANCY
The goal of input redundancy is to prevent failures outside the system from resulting in errors on input cards.
Input redundancy is managed by the Man Machine Interface (MMI) board which determines when to switch:
•
From one service (
Main
) to another service (
Backup
), or
•
From one port (
Main
) to another port (
Backup
).
However, it is possible that both these services and ports have different content.
Input
Input port or service; the notation is <X:Y:Z> where:
•
X
–
input module’s slot position
•
Y
–
input module’s port
•
Z
–
service SID
Backup Input
Backup input port or service; the notation is <X:Y:Z> where:
•
X
–
input module’s slot position
•
Y
–
input module’s port
•
Z
–
service SID
Type
Type of input redundancy, either
Service
or
Port
.
Mode
Displays the switching mode being used.
